Spearman correlation (top panel) and partial correlation (bottom panel) between transgene protein per RNA levels and GC content for each codon position.

Transgene data from Cambray and colleagues [41]. Partial Spearman correlations are controlling for the influence of all other codon positions in the available construct sequence (codons 2–30) such that, for instance, the relation between transgene expression (as protein/RNA) and GC content at codon 2 is found independently of the relation with GC content in codons 3–30. Stars represent P-value (p p p p p > 0.05 = no stars); “protein_by_RNA” refers to PNI/RNAss measures reported by Cambray and colleagues. Codon positions refer to absolute codon numbers (e.g., the start codon is codon 1). The data underlying this Figure can be found in https://doi.org/10.5281/zenodo.17378284. (CSV)